Cutting glass - would it work?
 

Hi,

I fear i am off on my next tangent. I stumbled across this site quite by accident and have not been able to pull myself away from it since.

What a fascinating machine !

Quick question though ; can a machine like this be used to cut glass sheets ? I want to cut float glass up to about 15 mm thick. I phoned around various manufactures to price CNC machines to cut glass and got quickly depressed and threw the whole idea out the window.......now i find this site and i am off on it again..oh dear.

I have not read through all the reams of information here yet, at least not too much of it but in what i have read I have found no reference to glass so far.

is it possible to cut float glass on a machine like this? I guess it would need some modifications to cut glass ?

Any comments most appreciated.

Regards

John Doe

Welcome John Doe,

Be aware, this MechMate is addicting. :)

On cutting glass, I also was interested. My wife does wonderful stain glass windows. I didn't think that a traditional glass cutter would work. This is just my gut feeling, and I'll experiment some time this year when my MM is up and running.

The other method I like is water jet cutting. This will work, but way more effort than I can handle at this time. I have done research on water jet cutting when I was a young engineer (so it will work), but I had better get a CNC machine operating first.

If I learn something about cutting glass, you'll be the first to know.

It will drag a diamond over glass with no problems. The rest is up to you. :)

The difficult part is getting force feedback on the Z axis. Robotic arms have this feature.

I better not go down that avenue. Let me get a MM cutting wood first. :)

Concerning the downward force control. Could you mount the glass cutter into some form of spring loaded head, thereby, having a floating cutter. I remember seeing something similar for engraving on an uneven surface, but this engraver had the whole rotating cutter mounted on a floating head. It seems that it might be easier to mount a stationary glass cutter of some type on to a floating head.
Just a thought..

Let's first see if our new Zambian friend is okay with scribing as opposed to cutting right through.

Hi all,

urrr, i'm not sure if scribing in itself is enough. First a disclaimer ; i have never cut glass before. Necessity is the mother of invention though and i need to build lots of stuff up here simply because little is available and anything you can actually get here is ridiculously expensive - hence i am a do it your selfer - not because i want to be , but because i have no choice.

With the glass i need several thousand glass fish tanks ( i export tropical fish from Zambia to the rest of the world). The absolute best pricing is to buy sheets of float glass from China. However that means i have to cut it into the sizes i need to make tanks. Hence a CNC cutter is just the ticket - me thinks. But now scbbing Vs cutting.....hmm not sure. I guess if you scribe it you can then break the glass along the cut but my first choice would be to cut the whole way through to make sure i get nice even square accurate cuts - much less wastage as well that way.

I'm up for the adventure to make the MM. What should i be considering in order to make a version that cuts glass all the way through ? If its doable , i'm in - whatever it takes.

Looks like lots of reading ahead and a steep learning curve.


Thanks for the replies so far.

Regards

JD

Methinks the Chinese will sell you ready-cut & polished edge glass far cheaper than you can dream of cutting & polishing yourself. Nevermind the logistics of getting big unbroken sheets of glass to Lusaka.

You could also probably get a Chinese plant to manufacture some tanks for you and ship them to your customers for you for relatively cheap in quantities of thousands. :)

Paul,
That's what I like about this site. I never considered a floating cutting head. Good food for thought.

I really want cut parts for my application. Some of these Tiffiny lamp patterns that my wife wants to make have thousand's of pieces in them. It sure would make life easier to have all the parts cut. The nice thing about water jet cutting is that the edges are ready for foiling. No grinding.

I have actually seen a huge CNC float class cutter in Germany. It scribed a line then pneumatically lifted a blunt "blade" up under the cut - the weight of the glass snapped it. The bed size was about 10m x 3m [32ft x 10ft] to accomodate sheets of glass that size! It was a one-man operation to fetch the sheet from the store, cut it and return it to the store. Vacuum grabbers, cranes and rotaters.

But the cleverest (and dumbest) innovation for me, and which could be used on MechMates, was the vacuum table for sucking the glass down. How did one man move that huge sheet of glass into the index position? . . .
.
.
.
.
. . . . reversed the vacuum and made it blow instead of suck - that glass glided like a hovercraft!

HI again,

Yes your right - to a degree. Its far cheaper to get the glass cut in China - except they cant/wont cut the sizes i need and try to force me to cut the sizes they want/have in stock. Very frustrating to get price lists and find the exact correct size sheet then be told they wont cut that size sheet for some obscure reason.

I need tanks by the lake and tanks in Lusaka. I need hundreds of 2x2x2 tanks and hundreds of 6x2x2 tanks plus many other sizes in between - a lot of glass. Still the glass is amazingly cheap in China - about 6.50 US per Sq meter ! (310 Rands per Sq mtr in JHB!!!) so its only 20 to 30 K in Glass - if i can find a way to cut it cost effectively ( read - accurate and little waste due to broken pieces because of breaking along scribe lines done manually - plus the labor skills up here are atrocious _ Gerald should know what i mean :-) )

I have tried every which way to get this moving. But for one reason or another it just does not come together. Hence i wonder about cutting my own glass to make all the tanks i need.

SO given this, whats involved to be able to cut glass all the way through ? If you say its not worth the effort involved , i will accept that and drop it. If it is doable i would love to "have a go" ( as we say in Australia)

As well we have lots of nice hardwoods up here. I wonder if solid wood cabinet doors could not be made ( would need a kiln though to dry the timber)

Ahh , maybe i am , as i said at the beginning off on a tangent that leads nowhere. However I would really love to cut my own glass using some sort of CNC/Laser setup.

Thanks for your thoughts

JD

Gerald

Your wife may well be interested in this video: http://www.youtube.com/watch?v=EKvWFZacQYA

As a stained glass worker myself, the video shows the type of cutter that I use, swivel head, oil filled. I anticipate that using a spring loaded head would be the main requirement when mounting. For non stained glass workers the glass is not normally flat, so there needs to be a relatively large 'spring' movement.

Bernard,
I think that was Gregs wife, not Geralds. :)

Thanks Bernard,

She really thought the video was "wild". Definitely gets ideas going. I'm still leaning towards a water jet system. She said something about cracking (my words, not hers) the glass pretty quick (60 seconds ?) after its "scorded". If you don't, the edges are not as good as they can be. I guess that's why I keep going back to the water jet method.

Let me get the first MM operational. Once I do, I'm thinking a CNC water jet could be the second MM. (I must be crazy :))

The z-slide has a large movement, and a pneumatic cylinder could easily provide a constant force . . . . just some ideas of possibilities.

By the way, Mach3 includes a facility for turning a "knife" tangential to the cut direction.

Hi,

Ok so lets say we went with scoring the glass only and do manual breaks , what sort of extra bits are involved over and above the normal MM ?

Waterjet sounds wild and gets the imagine going, but i wouldn't know where to start. Any pointers on this please or a direction i should head off to consider it further ?

Thanks for the replies. I must say, this is a wonderful little community you have going here.

Thanks

JD

John Doe,

Check out this site.

http://www.flowcorp.com/

Lots of good resources. A good primer.

Worked with (not for) this company 18 years ago. They were the experts then and it looks like they still are.

John,

A quick google of 'cnc glass cutting' yielded about 150,000 results. For your stated requirement of a through cut, water jet seems to be the professional method of choice.
If you really want to go the DIY route, I would have thought it more cost effective to use acrylic, at least that is workable with simple tools, but you're the ones who knows the trade offs.

hi

Water jets.....hmmm

Quote.......

" A mans mind once stretched by a new idea never returns to its original size"

Looks like i am sold on water jet. Now how to understand all this to see if we can fit a waterjet head on the MM....

Greg, it seems you are my ally here on this. Where do we go from here?

Gerard,

Could you please tell me before i get too excited about this, do you think it feasible to fit (somehow) a water jet head on the MM ?

This could be very vry awesome.

Regards

JD

I have never seen a waterjet head.

J.D.,

I have no doubt that a water jet can be mounted/modified for the MechMate.

I think the real issues are in the economics of a water jet for the DIY bloke (your rubbing off on me Gerald :) ) Water jet technology for cutting steel, or glass, or whatever is the way to go. The big advantage is in the secondary processes. You don't have the slag/smoke from flame cutting. You don't have a grinding process for glass cutting.

The negitive is in the cost of a water jet system. It is expensive. The cutting heads are special, etc. Now, I haven't studied this subject in a long time, so who knows what todays technology/market is.

I still have to get my router MM operational. Once I am off and running with that one, I'll start studying the water jet application. I'm thinking summer time frame (North American summer).

If I were you, I'd start with the internet and see what's available in your budget range. I've already checked ebay to see if there was any water jet technology equipment. Nothing.

Anyways, I not much help today, but let me get one project completed, then I'll be more than happy to start a water jet MechMate.

John,

Before you get too excited, water jet equipment hardly falls into the easy diy range, you are talking pressures up to the 50,000 psi range and for glass you will need an abrasive solution. Used systems tend to be for the whole package, haven't seen any just for just the pump part of the system.

Mechanically the transport system needs to drag around high pressure hose, which I suspect would require a lot of research and quite probably a lot of re-design.

BarnardR,

Good points. Specially the "hardly falls into the easy diy range" It is difficult.

The system I worked with operated at 90,000 psi. Talk about a "kid in a candy store" project for a young engineer.

Maybe that difficult aspect is why I want to begin studing a water jet MechMate. The tough projects are the most rewarding. We'll see.

J.D.,

This is where I'm starting. Its Amazon.com books.

http://www.amazon.com/s/ref=nb_ss_gw...ting&x=17&y=18

J.D.,

Get familiar with this organization.

http://www.wjta.org/

Gerald: If this is getting to "off topic" from the MM, just let me know.

JD,

I found a Rexroth water jet pump on EvilBay for $500 (five hundred):

110220623343

Don't know about the hoses and nozzle, but I bet they could be found as well. While the MM could probably be re-engineered for this purpose, there would be some interesting problems to work through - how deep/heavy would the water tray need to be? Putting out 50K + psi, how would you keep the gantry on the rails!!!!!

Interesting to think about ....

Brian

Brian

Probably more information than you need!!!
http://www.waterjets.org/about_abrasivejets.html

Have a look at this. Don't know if it is any good.

http://www.solsylva.com/cnc/misc.html Right at the end.

Glass cutting